The Near-Real-Time SSM/I-SSMIS EASE-Grid Daily Global Ice Concentration and Snow Extent (NISE) data set, available from the NASA National Snow and Ice Data Center Distributed Active Archive Center (NSIDC DAAC), now includes data derived from all available Special Sensor Microwave Imager/Sounder (SSMIS) sensors. Version 5 of the NISE data set contains data from the F18 SSMIS sensor. The newly released data from the F16 and F17 will be provided in Version 3 and Version 4, respectively. Data from F16, F17, and F18 will all be updated in near-real-time as new data are processed.
NSIDC investigated increasing snow extent differences over time between both NISE v3 (created from F16) and NISE v5 (created from F18) and NISE v4 (created from F17). While small inconsistencies are expected between sensors, these evolving differences warranted an update to the NISE v3 and NISE v5 snow extent algorithm to improve the consistency of NISE v3 and v5 data sets. Details about the algorithm updates are included in the v3 and v5 documentation. NISE is a quasi-operational product and thus is not meant for long-term climate monitoring. The NISE v3 and NISE v5 snow extent algorithm was updated 1 September 2021. Note that no changes were made to the sea ice concentration algorithm.
Version 5, created from F18 Data set DOI: https://doi.org/10.5067/3KB2JPLFPK3R
Version 4, created from F17 Data set DOI: https://doi.org/10.5067/VF7QO90IHZ99
Version 3, created from F16 Data set DOI: https://doi.org/10.5067/JAQDJKPX0S60